What to Do With a Thanksgiving Cactus in August Before It’s Too Late to Create a Fuller, Flower-Filled Holiday Display

If your Thanksgiving cactus has spent summer growing quietly, August is the time to prepare it for a spectacular fall display. Although little may seem to be happening above the soil, the plant is shifting from active growth to preparing for its late-season blooms.

A few simple adjustments to your Thanksgiving cactus care routine can make all the difference as the days begin to shorten. Unlike many houseplants that simply continue growing through late summer, this seasonal bloomer benefits from changes to watering, feeding, and light conditions that encourage healthy growth and maximize flowering.

Whether your plant lives indoors year-round or has been enjoying a summer vacation on a shaded patio or porch, these are the essential August jobs to check off.

1. Keep Watering, but Don't Overdo It

During August, your Thanksgiving cactus is still actively growing, so it shouldn't be allowed to dry out completely. At the same time, it dislikes sitting in wet potting mix. If you already know how and when to water a Christmas cactus, the same principles apply here, as both holiday cacti prefer evenly moist soil during the growing season rather than constantly soggy conditions.

Water thoroughly only when the top inch of soil feels dry to the touch. Allow excess water to drain away completely, and never let the pot sit in a saucer full of water, as constantly wet roots can quickly lead to root rot. If your home or outdoor space is particularly warm, the potting mix may dry out faster than earlier in the summer, so it's worth checking moisture levels regularly rather than watering on a fixed schedule.

If you're unsure whether your plant needs a drink, a simple soil moisture meter can help take the guesswork out of watering. The Luster Leaf Rapitest Moisture Meter from The Home Depot measures moisture levels at the root zone, helping prevent both overwatering and underwatering. Likewise, a long-spouted watering can, such as the Bloem Aqua Rite Watering Can from Amazon, makes it easy to direct water onto the potting mix without splashing the stems or leaving excess moisture trapped between the plant's segments.

2. Give It One Last Feeding

August is generally the final month to fertilize a Thanksgiving cactus before flower buds begin to form. If you already fertilize houseplants throughout the growing season, continue feeding your Thanksgiving cactus with a balanced liquid fertilizer, but plan to stop by late August or early September so the plant can transition naturally into its blooming cycle.

Apply the fertilizer at half strength every few weeks during active growth. Continuing to fertilize too late in the season encourages leafy growth rather than flowers, so easing off as fall approaches helps direct the plant's energy toward bud production.

If you're looking for an easy-to-use fertilizer, Miracle-Gro Succulent Plant Food, available from Amazon, is formulated for cacti and other succulents and can be applied every two weeks during the active growing season.

For a more general indoor plant fertilizer, Miracle-Gro Indoor Plant Food, available at The Home Depot, is another good option. Its balanced liquid formula can be diluted or applied directly to the soil, making it suitable for Thanksgiving cacti during their final feeding before bloom season.

3. Check for Pests Before Bringing Outdoor Plants Indoors

Many gardeners move their Thanksgiving cactus outdoors for the summer, where it benefits from brighter indirect light and better air circulation. If yours has been outside, inspect it carefully before bringing it indoors later in the season.

Look closely for:

• Mealybugs hiding where stem segments join
• Scale insects attached to stems
• Spider mites on stressed plants
• Slugs or snails sheltering beneath containers

Wipe the stems with a damp cloth and treat any pests promptly before they spread to your other houseplants. For light infestations of common houseplant pests, Safer Brand Insect Killing Soap, available on Amazon, is a useful option. It's formulated for use on ornamental plants and can help control soft-bodied insects such as mealybugs and spider mites when used according to the label directions.

4. Hold Off on Repotting Unless It's Absolutely Necessary

Although August is still part of the growing season, it's usually best to avoid repotting a Thanksgiving cactus unless it's severely root-bound or the potting mix has completely broken down. If you need to repot a cactus, remember that holiday cacti are happiest when slightly root-bound, so only move your plant into a larger container when it's genuinely outgrown its current one.

Repotting late in the season can temporarily interrupt growth just as the plant begins preparing to produce flower buds. If repotting is unavoidable, choose a container just one size larger than the current pot and use a well-draining cactus or succulent potting mix. Mixing in extra perlite or orchid bark can improve drainage even further.

A ready-made mix, such as Miracle-Gro Cactus, Palm & Citrus Potting Mix from Amazon, provides the fast-draining conditions Thanksgiving cacti need and can be amended with extra perlite if you want to improve aeration even further.

5. Start Thinking About Fall Light Conditions

Flower buds don't appear by chance. Thanksgiving cacti bloom in response to a combination of cooler temperatures and longer nights. While August is often too early to begin a strict bud-setting routine, it's a good time to plan ahead.

If your plant has been outdoors, bring it inside before nighttime temperatures consistently fall below about 50°F (10°C). Once indoors, bright indirect light during the day and long, uninterrupted periods of darkness at night later in the season will help trigger bud formation. If you don't have a naturally bright location, a GooingTop LED Grow Light, available on Amazon, can provide supplemental light during the day without exposing the plant to harsh direct sun.

Once buds begin to develop, avoid moving the plant unnecessarily, as sudden changes in light, temperature, or humidity can cause buds to drop before they open. If your home tends to be dry once the heating comes on later in the season, a compact humidifier such as the Levoit Smart Warm and Cool Mist Top-Filled Ultrasonic Humidifier and Diffuser, available from The Home Depot, can help maintain more consistent humidity around your houseplants without overwatering the soil.

6. Clean the Foliage

Dust and debris can build up on stem segments over time, especially on indoor plants. If you already clean houseplant leaves as part of your regular plant care routine, don't overlook your Thanksgiving cactus. Giving it a quick clean helps maximize photosynthesis while making it easier to spot pests or signs of disease before they become a bigger problem.

Use a soft, slightly damp microfiber cloth to gently wipe each stem segment clean. A set of Amazon Basics Microfiber Cleaning Cloths, available from Amazon, is ideal for gently removing dust without damaging the delicate stem segments. Avoid commercial leaf-shine products, which aren't suitable for the plant's flattened stems.

Removing any damaged or shriveled segments at the same time will also help keep the plant looking its best heading into bloom season. Keep a pair of Fiskars Micro-Tip Pruning Snips, available at The Home Depot, nearby for making clean, precise cuts when trimming away dead or damaged growth.

FAQs

Should I Prune My Thanksgiving Cactus in August?

Light pruning is fine if you want to encourage a fuller, bushier plant, but avoid removing too much growth late in the season. Major shaping is best done after flowering, giving the plant plenty of time to produce new stem segments before the next blooming cycle.

Can I Leave My Thanksgiving Cactus Outside in August?

Yes, Thanksgiving cacti often thrive outdoors during August, provided they're kept in bright shade or filtered light and protected from hot afternoon sun. Keep an eye on nighttime temperatures as summer winds down, and move the plant indoors before temperatures consistently drop below 50°F (10°C). With just a few simple care adjustments, August serves as the bridge between summer growth and the blooming season ahead. Keeping your Thanksgiving cactus healthy, well-watered, and free from pests now gives it the best possible chance of producing a colorful display just in time for Thanksgiving.